REMOVAL OF CALCIUM FROM CRUDES

EXTRACTION DE CALCIUM DE PETROLES BRUTS

English Abstract

The present invention is a process to remove a +2 ionic charged metal from a
petroleum feed. The process includes contacting the
feed with a resin that includes carboxyl, sulfonic and/or phosphonic groups.
In a preferred embodiment the metal is a Group II metal. In
particular, the metal is calcium.

French Abstract

La présente invention concerne un procédé destiné à extraire un métal chargé d'ions 2<+> d'une charge d'alimentation en pétrole. Ce procédé comprend la mise en contact de la charge d'alimentation avec une résine comprenant un groupe carboxyle, sulfonique et/ou phosphonique. Dans un mode de réalisation préféré, ce métal appartient au groupe II. En particulier, ce métal est du calcium.

Claims

-4-
CLAIMS:
1. ~A process to remove +2 ionic charged metals, Ca, Mg, Mn, and Zn, dissolved
in an
oil phase of a petroleum feed comprising (a) contacting said feed with an oil-
insoluble
resin, the oil-insoluble resin being carboxyl, sulfonic, or phosphonic groups,
or
combinations thereof, and (b) separating said resin from said petroleum feed,
thereby
lowering the metal concentration in said petroleum feed.
2. ~The process of claim 1, wherein said resins are cross-linked.
3. ~The process of claim 1 or 2, wherein said resin includes sulfonated
styrene-
divinylbenzene copolymers, methacrylic acid-divinylbenzene copolymers,
polyacrylic
acid, polyvinylsulfonic acid, phosphorylated styrene-divinylbenzene
copolymers,
polymethacrylic acid and styrene-divinylbenzene copolymers with attached
iminodiacetic
acid groups.
4. ~The process of any one of claims 1 to 3, wherein said charged metal is
calcium.
5. ~The process of any one of claims 1 to 4, wherein said resin is in the form
of a bed
through which said petroleum feed is passed.
6. ~The process of any one of claims 1 to 4, wherein the resin is suspended in
the
petroleum feed and separated at the end of the treatment by filtration or
centrifugation.
7. ~The process of any one of claims 1 to 6, wherein said process is carried
out at a
temperature between 50°C and 150°C.
8. ~The process of any one of claims 1 to 7, wherein said charged metal is in
the form
of naphthenates.
9. ~The process of any one of claims 1 to 7, wherein said charged metal is in
the form
of phenolates.

-5-
10. The process of any one of claims 1 to 7, wherein said charged metal is in
the form
of chlorides.
11. The process of any one of claims 1 to 7, wherein said charged metal is in
the form
of sulfates.

Description

CA 02266433 2003-03-26
-1-
REMOVAL OF CALCIUM FROM CRUDES
BACKGROUND OF THE INVENTION
The present invention relates to a process to remove certain metals
from crude oil. In particular, the metal is calcium.
Calcium present in crudes can lead to fouling of heaters and heat
exchangers and poison catalysts used in crude processing. Therefore, Ca-rich
crudes are less vaiuabie than cruder with low Ca. A process for Ca removal
enables the increase of the value of such cruder. This invention is
particularly
valuable when a Ca-rich crude is processed in a corrosion-resistant
environment,
where the increase in acidity accompanying the process of the present
invention
is not a drawback.
SUMMARY OF THE INVENTION
The present invention is a process to remove a +2 ionic charged
metal from a petroleum feed. The process includes contacting the feed with a
resin that includes carboxyl, sulfonic andJor phosphoric groups. In a
preferred
embodiment the metal is a Group II metal. In particular, the metal is calcium.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a process to remove +2 ionic charged
metals from a petroleum feed. The metals include Ca, Mg, Mn, and Zn.
Calcium is particularly important. The process includes contacting the feed
with
a resin that includes carboxyl, sulfonic and/or phosphoric groups and
separating the
resin from .the feed. These metals may be in several forms, including
naphthenates,
phenolates, chlorides or sulfates.
The resins can contain carboxyl, sulfonic or phosphoric groups.
Preferably, the resins are crosslinked, therefore not soluble in the crude.
Suitable resins are sulfonated styrene-divinylbenzene copolymers, methacrylic
acid-divinylbenzene copolymers, polyacrylic acid, polyvinylsulfonic acid,

CA 02266433 2003-03-26
-2_
phosphorylated styrene-divinylbenzene copolymers, polymethacrylic acid and
styrene-divinylbenzene copolymers with attached iminodiacetic acid groups.
The resin can be in the form of a bed through which the crude is
passed; otherwise, the resin can be suspended in the crude and separated at
the
end of the treatment by filtration or centrifugation. The temperature at which
the
treatment occurs should be high enough to reduce the viscosity of the crude
and
low enough to avoid decomposition of the resin. A temperature between 50 and
150°C is generally satisfactory.
After use, the resins can be regenerated by acid treatment.
The following examples illustrate the invention without limiting it.
Examgle 1
The reaction apparatus was a glass vessel equipped with stirrer and
reflux condenser, immersed in an oil bath. 50 g of Korrie 6/1 crude,
containing
930 ppm of Ca, 42 ppm of Mn and 2.6 ppm of Zn were put into the reactor. 15.6
g of sulfonated sty,~Mne-divinylbenzene copolymer, known under the commercial
name of Amberlite IR-120 and having a capacity of 1.9 milliequivalents/ml,
were
added.
The mixture was stirred at 70°C for 7 hours. Then the solid was
separated by centrifugation and the treated crude was analyzed for metals. The
contents of Ca, Mn and Zn had dropped to 107, 4.9 and 0.9 ppm respectively.
Infrared spectroscopy showed that the band at 1708 cm-1,
corresponding to the carboxyl group, is more intense than in the untreated
crude
and the band at 1600 cm-l, corresponding to the naphthenate, was less intense
than irr the untreated crude. This showed that the metals were in the form of
carboxylates and that metals removal had freed carboxylic acids.
We believe the following reaction has occurred:

CA 02266433 2003-03-26
-3-
Ca'~"~' +2 S03H -~ 2t..t+ + S03 Ca
2
Example Z
The reaction apparatus was the same as in Example 1. 50 g of
Kome 6l1 crude was put into the reactor. Then 2.15 g of a copolymer of
methacrylic acid with divinylbenzene, known under the commercial name of
Amberlite IRP-64 and having a capacity of 10 milliequivalents/g, were added.
The mixture was stirred at 70°C for 6 hours. Then the solid was
separated by centrifugation and the crude was analyzed. The contents of Ca, Mn
and Zn had dropped to 66, 2.2 and 0.7 ppm respectively.
We believe the following reaction has occurred:
Ca'~'~' +2 COOH ----~ 2H+ + COO Ca
2
Example 3
The reaction apparatus was the same as in Example 1. 50 g of
Kome 6/1 crude were put into the apparatus. Then 7.6 g of a sulfonated styrene-
divinylbenzene copolymer, having a capacity of 3.3 milliequivalents/gram and
known under the commercial name of Amberlyst XN 1010 were added.
The mixture was stirred at 70°C for 7 hours. After separation of
the solids by centrifugation, the oil contained 147 ppm of Ca, 9 ppm of Mn and
.7 ppm of Zn, i.e. much less than in the untreated Kome 6/1.